The present invention is directed generally to a computer-user interface, and particularly to a pneumatic clicker for a computer.
A conventional computer input device, such as a mouse, requires the user to employ a single hand in order to simultaneously perform the following two tasks: a) moving a cursor on a computer screen by manipulating the rotation position of a sphere mounted within the input device relative to the position of the main body of the input device; and b) entering the current location of the screen cursor into the computer by activating a clicking key on the input device using a selected finger of the user's hand, thereby activating various operations such as screen commands, scroll functions and layout changes.
The first of the two tasks, namely manipulating the rotational position of the said sphere relative to the said device, does not involve a particular threat to the operator's health, as the physical movements required of the operator are slight, intermittent and randomly directed. However, the second of the two tasks, namely activating the clicking key, is a frequent and highly repetitive physical task. As the tendons and muscles of the hand, wrist and forearm are relatively small, they are particularly vulnerable to injuries associated with the such a repetitive motion.
Increasingly, as more tasks are being performed on computers, and computer operating systems tend towards the use of a graphical user interface, many people activate the clicking key of an input device, hundreds, even thousands, of times per day. This situation has led to a dramatic increase in injuries related to the repetitive motion required of the small muscles and tendons of the fingers, wrists and forearms.
The following discussion of related problems refer to FIG. 1. When overused, the tendons 26 connected to the finger 27 responsible for activating the "clicking" key 6 of the mouse 5, become swollen, causing discomfort and numbness in the finger 27. This inflammation of the tendons, commonly known as "tendinitis," is a debilitating condition which can only be corrected by prolonged abstinence from any activity involving the injured tendon. This may mean avoiding meaningful use of the finger 27 for weeks or even months to recover.
The tendons 26 of the finger 27 pass through a fibrous sheath 28 in the wrist 33 called the "carpal tunnel." If scar tissue develops within the sheath 28, as a product of repeated overuse of the tendons 26 in the finger 27, pressure is placed on all of the nerves passing through the tunnel 28. This phenomenon, called "carpal tunnel syndrome," is a seriously debilitating condition whose symptoms include varying degrees of numbness, swelling and pain in the affected hand 30 and fingers. Often this condition requires surgery to relieve the pressure on the nerves. After surgery, the wrist 33 is typically cast for a period of time, followed by a period of rehabilitation.
A muscle group 29, located in the forearm 31, is responsible for activating the tendons 26 which, in turn, activate the "clicking" finger 27. If this muscle group 29 becomes fatigued through repeated "clicking," it may become inflamed, causing pain in the surrounding area. Like tendinitis, treatment of this muscle inflammation requires abstinence from the offending activity, followed by a period of rehabilitation.
Referring now to FIG. 2, conventional use of a mouse 205 requires that the computer user's hand 230 stay in close physical contact with the device, since the user's index finger 227 must frequently activate the "clicking key" 206 in order to perform the aforementioned tasks. The result is that the user's hand 230 tends to grip or press against the mouse 205 for prolonged periods. With the hand 230 arched in this way, the wrist 233 tends to drop, creating an unnatural curvature 209 between the hand 230 and forearm 231. The forearm 231 tightens in response to hand tension. Eventually, the tension can travel to the shoulder 210 and neck 211 muscles. Stiffness, fatigue, and irritability are the frequent results.
Many people use computer input devices as a routine part of their work day. Therefore, following an injury, they risk losing their livelihoods if they do not return to their computer related activities in a timely fashion. Unfortunately, a premature return to the offending activity often leads to a relapse of the injury.
It should be noted that all ailments of the finger, wrist or forearm present particular hardships for those who suffer from them, not only because of time missed from work, but also in their everyday lives, as most activities require the use of the hands. Moreover, return to the offending activity often leads to a relapse of the condition.
Problems inherent with the conventional use of computer input devices include risk of tendinitis, carpal tunnel syndrome and muscle inflammation. Less severe symptoms include stress and fatigue. The risk of developing these conditions increases proportionately with the amount of activity required of the user. The toll on those who suffer from these problems include loss of productivity, psychological stress, chronic pain and costly rehabilitation. An employer loses productivity and employees lose morale. Finally, the costs associated with diagnosis, treatment and rehabilitation are considerable, not only to the employer and employee but also on the medical system as a whole.
Therefore, there is a need for affordable computer accessories available that will allow an individual afflicted by the injuries described above to return to their computer related activities in a fashion that will not reinjure or further aggravate their injuries. Furthermore, there is a need for inexpensive, easily adaptable computer accessories available that will augment a computer input device so that the small muscles and tendons of the hand and wrist are exempt from the high risk activity associated with activating the clicking key, thus preventing injury from occurring in the first place.